Ashton Kutcher is reported to have signed a deal to replace Charlie Sheen on Two and a Half Men. Photograph: Reuters

Ashton Kutcher is perhaps most famous for his elaborate practical jokes on fellow celebrities on MTV's Punk'd. But Twitter's most popular Hollywood star is now being lined up to star in the biggest sitcom on US television as the replacement for Charlie Sheen in Two and a Half Men.

Kutcher appeared to confirm the answer to one of the most speculated over questions in showbiz on Friday – who will replace Sheen following his all-too-public meltdown – with a Twitter message hinting at his role as the popular comedy's new lead man.

Kutcher, who is married to the Ghost star Demi Moore, is widely expected to be unveiled as the show's new lead man as early as Wednesday, when CBS parades its new programming schedule in a glitzy presentation before advertisers in New York.

Sheen's abrupt departure from the popular prime-time comedy in March prompted weeks of frenzied speculation over his replacement. Hugh Grant was reported to have pulled out of 11th-hour negotiations over "creative differences".

CBS and Warner Bros, the studio behind the show, have been scrambling to reinvent Two and a Half Men with a big-name actor ahead of the TV network's big industry show on Wednesday. People reportedly familiar with the show's plans have played down the news that Kutcher is set to replace Sheen on the show, insisting that his role will be newly created.

Two and a Half Men is the most-watched TV comedy in the US with about 15 million regular viewers. But some have questioned whether the show will ever be the same without its truculent frontman.

Kutcher, 33, shot to fame as the dim-witted stoner, Michael Kelso, in That 70s Show, which ended in 2006. The former model's film career has been less than glittering, with a series of underwhelming comedies including Just Married, Guess Who, and Dude, Where's My Car?

CBS and Warner Bros could not be reached for comment at the time of publication.

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